Skip to main content
SearchLoginLogin or Signup

Does strength help Pluto capture Charon?

Presentation #308.09 in the session Pluto System (Oral Presentation)

Published onOct 23, 2023
Does strength help Pluto capture Charon?

The origin of the Pluto-Charon binary is generally assumed to be a giant impact, though the conditions of this impact, including the impact velocity, pre-impact spin, and composition of the progenitor bodies, are the subject of ongoing work. Previous impact simulations using strengthless progenitors have demonstrated collisional capture of a Pluto-Charon-like system (Canup 2005, 2011, Arakawa et al., 2019). However, these simulations require specific initial conditions that are difficult to reproduce with similar models. Ongoing developments in smoothed-particle hydrodynamics (SPH) codes have improved resolution capacity as well as treatments of material interfaces and, most importantly, incorporated material strength. Additionally, the arrival of New Horizons massively expanded our understanding of the interior properties of both Pluto and Charon, including the potential distribution of material in their interiors, while possibilities for their thermal evolution remain quite broad (e.g., Bierson et al., 2020). Here, we present the results of Pluto-Charon-forming simulations using updated interior estimates, including an ice-rich Charon, as well as incorporating material strength in the form of solid friction, which is now known to be important in the size range that encompasses large Kuiper Belt Objects (e.g., Leinhardt et al., 2010). Building on prior modeling efforts, we consider whether the use of material strength will facilitate graze and capture resulting from giant collisions, using a new set of parameter explorations that vary material strength, including the pre-impact thermal structure of the parent bodies, as well as pre-impact rotation of impactor and target. We propose that the role of material strength, and its strong reliance on temperature in icy bodies and ocean worlds, can be critical in determining whether a giant impact produces a satellite.

No comments here